허리 관절을 갖는 4족 로봇의 경사면 보행을 위한 걸음새 생성 방법

김국화(Guk Hwa Kim),최윤호(Yoon Ho Choi),박진배(Jin Bae Park) 한국지능시스템학회 2012 한국지능시스템학회논문지 Vol.22 No.5

본 논문에서는 4족 로봇의 허리 관절을 이용하여 효율적인 경사면 보행을 위한 걸음새 생성 방법을 제안한다. 허리 관절을 갖는 4족 로봇의 기구학적 모델은 Denavit-Hartenberg 표현 방법과 대수적 방법을 이용하여 유도하고, 다리 이동 순서는 물결 걸음새(wave gait)를 사용한다. 한편 제안한 걸음새 생성 방법에서는 기구적 제한과 보폭의 감소를 완화하기 위해 경사면의 경사도에 따라 적절한 상체 및 하체의 허리 관절각을 결정하고, 에너지 안정도 여유(energy stability margin)를 증가시키기 위해 도달 영역(workspace)의 탐색을 통해 발끝 위치를 결정한다. 마지막으로, 컴퓨터 모의 실험을 통해 본 논문에서 제안한 알고리듬의 효용성 및 실제 적용 가능성을 검증한다. In this paper, we propose a gait generation method for a quadruped robot to walk efficiently on the slope, which uses the waist joint of a quadruped robot. We derive the kinematic model of a quadruped robot with waist joint using the Denavit-Hartenberg representation method and the algebraic method. In addition, the gaits are generated based on the wave gait. In the proposed gait generation method, first in order to alleviate the mechanical restriction and the reduction of the stride, we determine the appropriate waist joint angle according to the slope degree, and then decide the location of the tiptoe of a quadruped robot by exploring the workspace. Finally, through computer simulations, we verify the effectiveness and applicability of the proposed method.

요가지도자의 비언어적 커뮤니케이션이 수련자들의 감정반응과 신체이미지에 미치는 영향

김국화 ( Guk-hwa Kim ),민현주 ( Hyun-joo Min ) 대한무용학회 2016 대한무용학회논문집 Vol.74 No.6

This research have aims at investigating the effect of yoga instructor`s nonverbal communication on trainees` em otion reaction, and sense of the self. We did reliability analysis, frequency analysis, member variable analysis, interrelation analysis, and multiple/periodic recurrence analysis. As a result, firstly, instructor`s physical, space, mind, and outward language had positive influence that led to right effect on participants. Space, mind, and outward language somewhat had negative influence on participants. Secondly, instructor`s outward language gave positive outcomes in both social and emotional self. Physical language had positive influence in finding physical self while mind, and outward language had negative influence.

항공사 비정상 운항 복구를 위한 리-타이밍 전략과 개미군집최적화 알고리즘 적용

김국화(Guk hwa Kim),채준재(Jun jae Chae) 한국산업경영시스템학회 2017 한국산업경영시스템학회지 Vol.40 No.2

Airline schedules are highly dependent on various factors of uncertainties such as unfavorable weather conditions, mechanical problems, natural disaster, airport congestion, and strikes. If the schedules are not properly managed to cope with such disturbances, the operational cost and performance are severely affected by the delays, cancelations, and so forth. This is described as a disruption. When the disruption occurs, the airline requires the feasible recovery plan returning to the normal operations in a timely manner so as to minimize the cost and impact of disruptions. In this research, an Ant Colony Optimization (ACO) algorithm with re-timing strategy is developed to solve the recovery problem for both aircraft and passenger. The problem consists of creating new aircraft routes and passenger itineraries to produce a feasible schedule during a recovery period. The suggested algorithm is based on an existing ACO algorithm that aims to reflect all the downstream effects by considering the passenger recovery cost as a part of the objective function value. This algorithm is complemented by re-timing strategy to effectively manage the disrupted passengers by allowing delays even on some of undisrupted flights. The delays no more than 15 minutes are accepted, which does not influence on the on-time performance of the airlines. The suggested method is tested on the real data sets from 2009 ROADEF Challenge, and the computational results are compared with the existing ones on the same data sets. The method generates the solution for most of problem set in 10 minutes, and the result generated by re-timing strategy is discussed for its impact.

요가지도자의 변혁적 리더십이 수련자들의 감정반응 및 수련만족도에 미치는 영향

김국화 ( Kim Guk-hwa ) 한국리듬운동학회 2021 한국리듬운동학회지 Vol.14 No.1

The purpose of study is aimed to give useful information in a yoga instructor exercising efficient leadership and to give basic data in improving the relational communication between a yoga instructor and a student. In order to achieve this objective, we used convenience sampling among women Yoga trainees whom attend the Yoga class at least once a week residing at Youngdong Gang-won-do area. Among those people, we eliminated incongruent data, and ended up with 291 people. For the data processing of this study, SPSS 21.0 was used for proceeding statistically, and for analyzing the data, this study conducted the reliance analysis, the correlation analysis, the multiple regression analysis. The results drawn from such analyses were as follows. First, it is shown that a yoga leader’s transformational leadership significantly influenced on participants emotional response. It was shown that a student’s positive emotional response resulting from the leader’s transformational leadership significantly influenced on the intellectual stimulation and the ideal influence power, but negative emotional response did not affect any significant influence at all. second, was shown that a yoga leader’s transformational leadership significantly influenced on participants class satisfaction. A student’s professor behavior satisfaction and self-accomplishment sense affected significant influence on the all variables of intellectual stimulation, individual consideration, and ideal influence power.

몸체 스웨이를 이용한 4족 로봇의 걸음새 생성

정학상(Hak Sang Jung),김국화(Guk Hwa Kim),최윤호(Yoon Ho Choi) 한국지능시스템학회 2012 한국지능시스템학회논문지 Vol.22 No.3

본 논문에서는 4족 로봇 몸체의 xz-축 스웨이(sway)를 이용하여 4족 로봇의 몸체 흔들림을 최소로 하고 안정도 여유를 최대로 하는 걸음새 생성 방법을 제안한다. 제안한 방법에서는 물결 걸음새(wave gait)를 기반으로 생성하고, 안정도 판별은 움직이는 다리의 높이 변화량과 4족 로봇의 몸체 기울기 정보를 이용한다. 이 때, 4족 로봇의 보행 시 z-축 스웨이로 인한 몸체의 충격을 줄이기 위해 푸리에 급수(Fourier series)를 이용하여 다리의 유연한 이동 궤적을 생성한다. 마지막으로, 본 논문에서 제안한 알고리듬의 실제 적용 가능성 및 효용성을 검증하기 위해 모의 실험 및 4족 로봇의 실제 보행 실험을 수행하여 제안한 방법의 보행 성능을 검증한다. In this paper, we propose a gait generation method for quadruped robots using the xz-axis sway of the quadruped robot, which minimizes the shake of the quadruped robot and maximizes the stability margin. In the proposed method, the gait is generated based on wave gaits and the stability analysis uses the body tilt information of the quadruped robot according to the leg"s height of leg. In addition, to reduce the impact on the body caused by the z-axis sway while walking, the proposed method generates the smooth walking movement trajectory with less impact by using Fourier series. Finally, to verify the applicability and effectiveness of the proposed method, we carry out the computer simulations and the real walking experiments with the implemented quadruped robot.

허리 관절을 갖는 4족 로봇의 GA 기반 경사면 보행방법

최윤호(Yoon-Ho Choi),김동섭(Dong-Sub Kim),김국화(Guk-Hwa Kim) 한국전자통신학회 2013 한국전자통신학회 논문지 Vol.8 No.11

본 논문에서는 허리 관절을 갖는 4족 로봇의 효율적인 경사면 보행을 위해 유전 알고리듬(Genetic Algorithm: GA)을 이용한 경사면 보행 방법을 제안한다. 제안한 방법에서는 먼저, 허리 관절을 갖는 4족 로봇의 기구학적 모델을 유도하며, GA를 수행하기 위한 유전자 및 적합도 함수를 설정한다. 또한, 경사면에서 최적의 에너지 안정여유도(Energy Stability Margin: ESM)를 갖는 4족 로봇의 자세와 도달 영역 내의 발끝착지 지점을 GA를 이용하여 자동으로 탐색하여 보행한다. 마지막으로, 4족 보행 로봇의 모의 실험을 통해 기존 방법과 비교함으로써 본 논문에서 제안한 방법의 효용성을 검증한다 In this paper, we propose a genetic algorithm(GA) based locomotion method of a quadruped robot with waist joint, which makes a quadruped robot walk on the slop efficiently. In the proposed method, we first derive the kinematic model of a quadruped robot with waist joint and then set the gene and the fitness function for GA. In addition, we determine the best attitude for a quadruped robot and the landing point of a foot in the walk space, which has the optimal energy stability margin(ESM). Finally, we verify the effectiveness of the proposed method by comparing with the performance of the previous method through the computer simulations

허리 관절을 갖는 4족 보행 로봇의 설계 및 모델링

김국화,최윤호 경기대학교 부설 산업기술종합연구소 2011 산업기술종합연구소 논문집 Vol.39 No.-